Although thermoplastic grocery bags have been utilized for over twenty years, only a very small percentage of the hundreds of patents have been embraced by industry to the point of significant commercial acceptance. Designing a thermoplastic bag, particularly with regard low or high density thermoplastic bags, can be a tedious and often unfruitful endeavor, as such material requires a design which allows its utilization as a bag for often heavy contents, which can cause stress fractures and bag failure. Further, the design should be able to be manufactured in an inexpensive, efficient, and consistent manner.
A list of prior patents which may be of interest is presented below:
Patent No. Inventor(s) Issue Date RE 33,264 Baxley et al. 06/17/1990 4,476,979 Reimann et al 10/16/1984 4,785,938 Benoit, Jr. et al 11/22/1988 4,811,417 Prince et al 03/07/1989 4,989,732 Smith 02/05/1991 5,074,674 Kulkies et al 12/24/1991 5,188,235 Pierce et al 02/23/1993
U.S. Pat. No. 5,074,674 to Kuklies et al teaches a bag comprising front and rear bag walls, the rear wall of the bag including an aperture centrally disposed between the handles and below the open top for reception by a retainer for supporting only the rear wall of the bag on the rack. The rear wall of the bag may have formed between the aperture and the bag mouth a "tear area" facilitated by a "preperforated line" (col 2, lines 36-40), which is indicated as not being required.
U.S. Pat. No. 5,188,235 to Pierce et al teaches a bag pack system for dispensing T-Shirt bags without the necessity of a detachable tab, claiming a "weakened portion comprising a severance line", contemplated in the specification as a vertical perforation extending between a generally horizontal central mounting aperture and a bag mouth. Thus, '235 requires the deliberate weakening of a linear portion of the bag structure above the mounting aperture to facilitate operation.
U.S. Pat. No. Re. 33,264 teaches a system wherein there is a detachable tab, unlike the present "tabless" system.